Manufacture of bobbin-spun rayon



Jan. 11; 1944. A, L JACKSQN 2,338,720

MANUFACTURE OF BOBBIN-SPUiW RAYON Filed June 26, 1942 4 Sheets-Sheet 1\i I at jllfiulilv #01301;

* w i W 1 A. 1.. JACKSON 2,338,720

MANUFACTURE OF BOBBIN-SPUN RAYON Filed June 26, 1942 4 Sheets-Sheet 2 1A. L. JACKSON 2,338,720

MANUFACTURE OF BOBBIN-SPUN RAYON Filed June 26, 1942 4 sheets-sheet aArifiurl. Jackson Jan. 11, 1944. v A L, ACKSON 2,338,720

MANUFACTURE OF BOBBIN-SPUN RAYON Filed June 26,- 1942 4 Sheets-Sheet 4 Pa-tented Jan. 11,

UNITED STATES PATENT OFFICE MANUFACTURE OF BOBBIN-SPUN RAYON Arthur L.Jackson, West Asheville, N. 0., assignor' to American Enka Corporation,Enka,-N. 0., a

corporation of Delaware Application June 26, 1942, Serial No. 448,655

14 Claims.

This application ,constitutes a continuation-inpart of my applicationsSer. No. 350,215, filed August 3, 1940, and Ser. No. 397,793, filed June12, 1941.

The present invention relates to the production of thread packages ofsynthetic origin, e. g.,

rayon, and is more particularly directed to an the bobbin-supportedwound body. Necessarily,

bobbin spinning is intermittent, for a spinning machine must be doffedafter the simultaneous preparation of a large number of thread packages;and, since each dofiing requires concomitantly the replacement of thefilled bobbins by empty ones and the threading up of each unit of themachine, it is inherently advantageous that the winding period, andtherefore the weight, of the packages be as great as possible consistentwith satisfactory after-treatment. Furthermore, since each bobbinundergoes the same amount of manipulation during after-treatment, it isin the interest of operating economy to treat as large amount of threadas possible on a single bobbin during each such operation. v

Previous efforts to attain the foregoing advantages have, in general,followed two lines. One of these involves the use of larger spools andthe other is concerned with the winding pattern of the thread.

The employment of large spools has not resulted in a solution of thebasic problem of bobbin spinning for, although it is obvious that abobbin of large size will hold more thread than a small one, there arelimits beyond which increases in bobbin size areno longer feasible.These limits are imposed by the structure of various units on which thethread is treated as well as by the structure of twisting machines onwhich the spinning bobbins are customarily placed upon completion ofafter-treatment. Then, too, during spinning, mechanical dimculties areencountered if the length of the bobb n is too great, the

being customarily supported from one end only and the thread beinglaid-up thereon of the courses of threads.

generally according to a pattern controlled by a reciprocating traversebar. Thus, the optimum bobbin size is now fairly well stabilized in therayon industry and recent efforts directed to the production of washablethread packages of me creased thickness and weight have been directed tocontrol of the winding operations.

The winding pattern schemes heretofore proposed in the interest ofproducing heavier and thicker packages of rayon thread susceptible tosatisfactory after-treatment have not met with commercial success,although some improvement in the washing qualities of smaller packageshas resulted. Usually, pattern control systems involve a cam-directedtraverse bar, the purpose of which is to control the manner in whichsuccessive layers of thread are laid up on the spimiing bobbin. Intheory, there have been several patterns suggested which should resultin the production of large packages of satisfactory size. In practice,however, this has not been the case, the packages produced beingcharacterized by nonuniform permeability. This non-uniformity may take anumber of forms. Thus, thread packages are frequently characterized byareas too dense to be washed at all, whileothers may be washed, but,because of differences in thickness along various radii of the packages,each after-treatmerit must becontinued for a period of time suflicientto properly wash the portions of greatest radial thickness, withresultant ineflicient waste the economy inherent in the preparation ofthread packages of substantial size, thickness, and weight,

Another problem which has stood in the way of the preparation of threadpackages of increased thickness arises from a mechanical diflicultywhich has heretofore been encountered. The yarn traverse mechanism whichlays up the thread on thespinning bobbin is, of course, subject toreciprocating movement. This movement inherently involves changes indirection and the shock incident thereto. In apparatus known to theprior art, the inertia at the points of changes of direction resulted in-overwimls in at least some Such overwinds are particularlyobjectionable in threads of low denier, i. e., below 300. To overcomethe dimculty, it has been customary to form thread packages with conicalends so that the slight variaassavao frame l3 of the machine. Each driveshaft II is I provided with a drive gear I9 meshing with and tions inthread course length will not cause driven bya gear 20. The gears 20,corresponding in number to the number of bobbins with which Anotherobject is the provision of a process and apparatus for the preparationof such packages.

According to this invention, it is contemplated thatthread consisting ofuntwisted filaments be u laid up in a cylindrical package form byapparatus so controlled as to accurately produce a desirable pattern anda package ,of uniform permeability throughout its entire axial length.

It is within the purview of this invention to greatly increase thewinding-on periods in the manufacture of bobbin spun rayon while, at theto the present invention;

Figure 2 .is a view in section taken along the line 2-2 of Figure 1;

Figure 3 is a view in section taken along the line 3-3 of Figure 2;

Figure 4 is a detail view taken along the line 4-4 of Figure 1;

Figure 5 is a view in section taken along the line 5-5 of. Figure 2;

Figure 6 is a View in longitudinal section through a portion of one typeof thread package which may be wound according to the present invention;7

Figure '7 is a view in longitudinal section of another type of .threadpackage which may be wound according to the present invention;

Figure 8 is a graphic illustration showing how' to produce peripheraldisplacement of the pattern as the thread is laid up on the bobbin; and

Figure 9 is an end elevation of the bobbin diagrammatically showing anend pattern with peripheral displacement whereby the ends areinterlocked and overwinds inherently prevented.

The illustrated apparatus consists of a plurality of driven foraminatedcollecting bobbins it! onto each of which'a freshly spun thread issuinfrom a spinning bath, not shown, is wound. The thread is laid up on eachpackage by a thread guide 1|, these guides being attached to and carriedby a traverse bar l2. Traverse bar |2 underlies-and reciprocates axiallyof bobbins Hi, the movement thereof being initiated by a cam l3.

It will be seen that each of the bobbins I8 is mounted on a bobbinholder l8 which is Provided with a drive shaft l5 mounted in bearings l6and 11 suitably attached to' portions of, the

, cam throughout its rotation.

the machineis provided, are keyed at spaced points along a shaft 2|mounted for rotation in bearings 22 and 23 supported by portions offrame l3. Shaft 2| constitutes the main drive shaft of the spinningmachine, rotation being imparted thereto through gear 24 driven from anysuitable s ource, not shown. It is of course, contemplated that saidsuitable power source may .operate through a variable speed transmissionso that the rotational speed of bobbins ID will be pro-' gressivelydecreased during the winding period to an extent suiilcient tocompensate for an increased takeup speed brought about by increase inthe effective diameter of the bobbin because of the body of thread builtthereon. Such variable speed transmissions for maintaining a constantbobbin takeup speed are per se known and form no part of this invention.An example of such an arrangement is shown and described in Patent2,159,032 to W. G. Lea. It is apparent, therefore, that when shaft 2| isdriven each of the bobbins 10 is caused to rotate and, since all gearsl9 and .20 are the same size, the speed of rotation of each bobbin illwill be equal to that of all other bobbins with which the machine isprovided.

Upon reference to Figures 1 and 2, it will be noted that,in addition togears 20 and gear 24, shaft 2| is likewise provided with a gear 25 thepurpose of which is to drive cam l3. The movement ofcam I3 is effectedthrough a speed reduction gear train consisting of gears 26, 21, 28, 29,30, and 3|. Gears 26 and 21 are keyed adjacent opposite ends of a shaft32 mounted in bearings 33 and 34. Gear 23 meshes with gear 23 andthrough shaft 32 drives gear 21. Gears 28 and 28 are mounted on stubshaft 35, gear 28 meshing with gear 21 and gear 29 serving to drive gear30 of larger diameter. Gear 30 is mounted on a shaft 38 and meshes withgear 3| mounted on hollow hub 31.

The hollow hub 31, in addition to supporting gear 3|, likewise supportsratchet 38 which'comprises part of an automatic tripping couplingmechanism hereinafter described. Ratchet 38 through pawls 33 drives disc40 which is keyed to shaft 4|. Shaft 4| in addition to. supporting disc40 likewise supports cam l3, the hub 42 of which is keyed thereto forrotation therewith. Inasmuch as shaft 8| must support cam l3 as well asdisc 40, bearings 43 and 44 ar provided, their design being such as toinsure proper absorption of axial as well as radial thrust.

It is now apparent that cam I3, although driven from shaft 2| whichdrives the bobbins l0, will rotate at a far slower speed than saidbobbins.

develop along a straight line, i. e., the linear" movement of itsfollower must always be directly proportional to the angulardisplacement of the In this way, the cam imparts to its follower areciprocating motion of substantially unvarying characteristics or, in

' groove, so cut as to insure movement of its follower 45 (Figure in alinear sense in direct proportion to the angular displacement of cam l3in its rotation with shaft 4|. The movement of the follower istransmitted unimpaired to the traverse bar by apparatus to behereinafter described.

Cam follower 45 is sup rted in a cross head 46 provided with aperturesfor the reception of rods 41 and 48 on which the cros head may freelyreciprocate while at all times being confined to movement in a singleplane. Rods 41 and 48 are rigidly held in spaced sleeves of a pair ofbrackets 49 and 50 which are attached to vertical portions of frame l8.

Arms 5|, see Figure 5, are pivotally attached to cam follower 45 at oneof their ends while, at the other end, they are pivotally attached tothe free endof a depending arm 52.

Arm 52 is attached, at its end remot from the location of the pivotalconnection to arms 5|, to a rock shaft 53 mounted in bearings 54 and 55atop frame l8. Depending from rock shaft 53 are arms 56 and 51 whichsupport traverse bar I2. The support of traverse bar I2 is not direct,however, as may be seen in Figure 2. At the ends of arms 56 and 5'!remote from the ends keyed to shaft 53 they are pivotally attached tohorizontally extending links 58 and 59 which in turn are pivotallyattached at their other ends to depending arms 60, only one of which canbe seen in Figure 2. Arms 60 are pivotally attached to a rock shaft 6|and serve to duplicate the movement of arms 56 and 51 on the oppositeside of the machine. Thus, in the interest of operating economy the leftside of 'the,spinning machin as viewed in Figure 2 may also be providedwith a series of bobbins and the laying up of thread thereon can becontrolled by cam l3. Because the links 58 and 59 are pivoted to thedepending arms 56, 51, and 60, the reciprocating motion ultimatelytransmitted to thread guide II will be in a single moving, substantiallyhorizontal plane thus preventing the guides from tilting in passing fromone end to the other on the spools.

Depending from links 58 and 59 are traverse bar supporting members 62and 63. Thus, when cam I3 is rotated, follower 45 reciprocates causingoscillation of shaft 53 through rocking arm 52. Oscillation of shaft 53,of course, causes reciprocation of traverse bar l2. that, although arm52 is susceptible to simple harmonic motion, the point of pivotalconnection of arms 5| thereto is so remote from shaft 53 as to maintainand transmit substantially unimpaired the movement of the cam follower.

It has now been shown that the production of a satisfactory windingcontrol movement of the traverse can be effected by the us of a cam ofstraight line development. It is further necessary,

' however, that the thread laid up on th bobbins exactly follow thepattern of movement of the traverse bar to render available thcharacteristics of cam I3. To this end, a novel type of thread guide hasbeen devised.

Referring again to traverse bar l2, it will be seen that said bar isprovided with a plurality of raised portions 64 underlying and in thesame vertical plane as the various bobbins In. A rod 65 is passedthrough each of th raised portions 64 and a hub 66 is pivoted thereto.Extending upwardly from each hub 66 is a fork 61 the tines of which areadapted to contact tangentially the respective bobbin. In order toinsure firm contact and at the same time to allow for increases inpackage diameter during winding, a counterweight 68 extends from eachhub 66 at a point diametrically opposite fork 61. The distance of theweight from the axis may be made adjustable to insure proper contactconsistent with avoidance of injury to threads having different char-'acteristics as regards resistance to abrasion. Be-

cause of the fact that the tines of each forked guide 61 actuallycontact the bobbin and the coils of thread wound thereon, there can beno substantial lag between th movement of the traverse bar and thethread directed thereby. Thus, the thread will follow accurately thepattern of movement of traverse bar l2 even during changes of direction,the break being sharp to insure avoidance of humps at the end of thepackage.

lA plurality of self-threading guides 69, see Figure 4, are attached totraverse bar l2, at spaced points along its length coinciding with thepoints of location of package contacting thread guides II. Theself-threading guides 69 are provided with a slot at 10 arranged belowand in registry with the slot defined by the tines 61 of thread guidesThus, in threading up, the pull between the thread source and thecollecting bobbin will'cause the thread to slide along the righthandsurface of guide 69, as viewed in Figure 4, thus pulling the thread intothe slot at 19. Guide 69 is provided with an extension received in asocket in traverse bar I2, the-extension serving to lock the guide inposition. A pin 12 consticharacterized by uniform permeability, uniformIt should be noted radial thickness throughout their axial length and bytheir self-supporting square ends. It is evident that because cam I3 andbobbins II) are each driven from shaft 2| they are driven insynchronism. The linear movement of the follower associated with cam |3is directly proportional to the angular displacement of said cam. Theconsequence of this is the production of truly helical coils throughoutthe entire winding period. While it is customary to reduce the speed ofshaft 2| progressively throughout the winding period so that theperipheral speed of the package will be maintained at a constant value,yet because both the bobbins and the traverse are driven from the sameshaft, the synchronism will be maintained. There will be no detrimentalrelative acceleration or deceleration of the traverse between reversalsof movement which will cause localized pattern distortion evidenced in'the final package'by humps and valleys at-each end thereof, the formerrequiring longer washing periods. The winding path being so accuratelycontrolled allows for very close winding with uniform intersticesthroughout the package which permit the passage of washing liquidtherethrough.

The apparatus thus far described provides packages having straightchannels throughout their axial length and are well suited \foraftertreating certain types of rayon. However, in forming packages ofviscose rayon particularly of low denier, objectionable overwinds at theends of the package may develop. Such overwinds of even the slightestmagnitude may cause tangling tionable overwinds.

or breaking or the threads. Therefore, in these cases, it iscontemplated to provide a package having the appearance illustrated inFigure 6 wherein there is shown a cylindrical package containing zigzagchannels throughout the axial length of the package. Referring to Figure9 it will be seen that there is circumferential displacement or angulardisplacement in a plane normal to the axis of the bobbin of succeedingportions of the pattern, as plotted in Figure 8, which interlocks theends of the package to prevent objec- Moreover, in this mode ofoperation, the passage of washing liquid is inhibited to some extent andthus the permeability still further controlled. I

In order to effect circumferential displacement of the pattern orsuccessive portions of the package, an automatic tripping coupling, seeFigure 2, is interposed between shaft 4| and main drive shaft 2|. Thefunction of this couplin is to periodically; momentarily stop therotation of shaft 4| and hence cam |3 driven therefrom. The trippingcoupling mechanism per se is shown more particularly in Figures 2 and 3,wherein the operation of the ratchet'and pawl construction 38 and 39 canbe seen. It has been previously stated that disc 48 is keyed to shaft 4|for rotationtherewith. Disc 48 is provided with an elongated sleeve-likehub portion 13 which overlies a short portion of shaft 4| extending fromthe disc in the direction of gear 3|. Hub 31 is mounted for rotationabout hub 13, as its bearing, hub 31 carrying in addition to gear 3|ratchets 38 and 14 all keyed for rotation therewith. Thus, in order toeffect the rotation of shaft 4| .in re sponse to-rotation of hub 31carrying driving gear 3| thereon, a mechanism composed of pawls 39 isinterposed between ratchet 38 and disc 48. Pawls 39 are pivotallyattached to disc 48 at 15 and are urged into engagement with ratchetwheel 38 by springs 16 attached to an arm 11 in turn attached andextending out from disc 48.

It will be noted that the pawls 39 are so arranged that only one pawl ata time is engaged by ratchet wheel 38, the remaining pawl being butpartially inserted into an adjacent tooth of the ratchet. It istherefore evident that by moving the driving pawl out of engagement withratchet 38, said ratchet will turn without moving disc 48 until theother pawl 39 abuts the driving edge of the tooth in which it waspreviously only partially received. During this period, the rotation ofshaft 4| will momentarily cease which will cause momentary cessation ofthe. movement of thread guide along bobbin |8. v

To effect intermittently the alternate displacement of pawls 39, a stargear 18 is employed, this gear drivin through a transmission, a disc 18on opposite sides of which are mounted pawl displacing pins 88 and 8|,each pinv acting on its respective pawl. Star gear 18 is mounted onshaft 82 which is attached to disc 48 through a bearing bracket 83. Theend of shaft 82 remote from star gear 18 has attached thereto a worm 84.This worm meshes with worm gear 85 mounted on stub shaft 88 anchored indisc 48, said stub, shaft also carrying gear 81. Gear 81 meshes withgear 88 mounted on stub shaft 88 and gear 88 likewise meshes with gear98 mounted on stub shaft 9|. The disc 19 carryingpins 88 and 8| is alsomounted on shaft 9| and is driven thereby.

The gear train comprising gears 84, 85, 81, 88 and 88 is set in motionby star gear 18. Pin 92 is disposed in the path of the star gear as itturns bodily with disc 48 and upon striking this pin gear 18 isangularly displaced. After a number of revolutions of shaft 82,dependent upon the gears in the transmission, one of the pins 88 or 8 8|will displace its pawl 39 thereby causing disc 48 and hence shaft 4| tostop by severance of the driving connection from ratchet 38. Pawl 93 isalso attached to disc 48 by pivotal connection to post 94 extendingtherefrom. Thispawl 18 engages ratchet wheel 14 and merely functions tokeep shaft 4| and disc 48 from turning ahead of driving ratchet 38.

The tripping oupling described above, when placed in operation, willcause momentary inter i5 mittent cessation of movement on the part ofshaft 4|. 0n the otherhand, because. of the position of the trippingcoupling the driving of bobbins I8 will continue uninterrupted. Theresult, therefore, of momentarily stopping the 20 rotation of shaft 4|,and consequently cam I3, is to interrupt the synchronism of the bobbinswith the traverse bar l2 driven from cam |3. Inasmuch as a pattern windis being produced by the driving synchronism, it will be seen that themomentary cessation of movement on the part of the traverse arm willresult in circumferential displacement of succeeding portions of thepattern produced with respect to previously wound portions thereof. i

In order to provide a package as shown in Figure 7, the automatictripping couplingmechanism, including the ratchet and pawl connection3939, maybe entirely eliminated and a direct connection interposedbetween the main drive shaft 2| and cam drive shaft 4|. If, however, therayon spinning machine has been constructed as fully disclosed hereinand it is desired to alter the normal operation thereof in order toprovide a package-Qas shown in Figure '7, then 0 the ratchet and pawl;connection 38--39 may be maintained throughout the entire winding-onperiod without eliminating the tripping coupling mechanism per se. Apackage having square-ends as used throughout the specification andclaims means a package in the form of a hollcw right cylinder. Theself-supporting feature with respect to the square ends is self-evident,i. e., the said ends are formed and retained in situ without any outsideinfluence such as thread contacting flanges" on the bobbins. The bobbinsemployed for the present invention may be the normal type insofar as theshape and construction are concerned,

bobbin, no' pattern formation is efiected as the arrangement of thediamonds is haphazard and occurs in a random manner throughout the body.

of the package.

18 Having now described the invention in its preferred form, it isunderstood that variations and modifications may be made therein withoutdeparting from the spirit of the invention, and it is desired that thescope thereof be limited only 18 by the spirit of the appended claims.

What is claimed is:

1. A uniformly permeable freshly spun, crosswound package of rayoncharacterized by a plurality of superimposed oppositely directed helicalcourses of thread, said courses being wound ac:

cording to a fixed pattern and throughout the body of the package atpredetermined points.

therein, layers of threads circumferentially dis-' placed with respectto layers therebelow; all of the layers constituting the body of thepackage being of substantially the same axial length'to form acylindrical package having self-supporting square ends and radiallyzigzag channels.

2. An abnormally heavy and thick, freshly spun, cross-wound package ofrayon threads of the order of 300 denier or more, each thread consistingofa plurality .of substantially untwisted filaments, said package beingfurther characterized by a plurality of oppositely directed helicalcourses of thread, said courses being wound onto a bobbin according to afixed pattern and superimposed 'on each other except at spaced radialpoints wherein certain layers are circumi'erentially displaced withrespect to other layers, all of the layers constituting the body of thepackage being of substantially the same axial length but shorter thanthe axial length of the bobbin to form a uniformly permeable,cylindrical package having self-supporting, interlocked square ends andradially zigzag channels.

3. A method for the preparation of truly cylindrical packages of freshlyspun rayon thread which comprises extruding afreshly spun thread througha coagulating bath and collecting the same on a bobbin at a substantialconstant linear speed and guiding it transversely across the surface ofthe package at a constant speed between reve'rsals of direction at anygiven time and from a point adjacent thereto, forming a permeablepackage on the bobbin by superimposing thereon a plurality of oppositelydirected helical courses of thread of equal axial length but shorterthan the axial length of the bob-bin, while maintaining a constant ratiobetween the rotational speed of the bobbin and rate at which the threadis laid transversely thereof whereby a predetermined fixed pattern iseffected throughout the winding period and a package is formed havingself-supporting square ends and radial channels throughout the bodythereof.

4. A method for the preparation of cylindrical packages of freshly spunrayon thread which comprises collecting a freshly spun thread on abobbin at a substantially constant linear speed and guiding ittransversely across the surface of the package from a point adjacentthereto, forming a permeable package on the bobbin by superimposing aplurality of oppositely directed helical courses of thread of axialequi-length thereon according to a predetermined fixed pattern and,throughout the winding period, circumferentially displacing the patternat intervals to form a package having self-supporting interlocked squareends and radially zigzag channels.

5. A bobbin spinning apparatus for winding freshly spun thread ofsynthetic origin into cylindrical packages having square ends whichcomprises a bobbin, a traverse member, a package contacting thread guidecarried by the traverse member and movable axially of the bobbin todirect laying up of the thread thereon, means for reciprocating thetraverse member at,a constant speed between reversals of direction atany given time and means for driving the bobbin and traverse member insynchronism and for maintaining the stroke amplitude of the traversemember constant throughout the winding period to produce a pattern windof constant axial length.

6. An apparatus for winding rayon packages in cylindrical form andhaving square ends comprising a bobbin, a traverse mechanism includ inga package contacting thread guide, means lor driving said bobbin andsaid traversemechanism in synchronism to produce a pattern wind andmeans forintermittently, circumferentially displacing successively woundportions of the portions of the pattern, a connecting means fortransmitting substantially unimpaired the said reciprocating motion tothe traverse member-and a package contacting thread guide carried bysaid traverse member and movable axially of the bobbin to direct thetransverse movementof the thread thereon.

8. An apparatus for the bobbin spinning of rayon comprising a bobbin, atraverse member, a cam for continuously producing reciprocating motionof unvarying characteristics, means for driving said cam and said bobbinin synchronism to produce a pattern wind, a connecting means fortransmitting substantiallyunimpaired the motion of said'cam to thetraverse member to effect a constant stroke amplitude throughout thewinding period, and a package contacting thread guide carried by saidtraverse member and movable axially of the bobbin to direct thetransverse movement of the thread thereon.

9. An apparatus for the bobbin spinning of rayon comprising a bobbin, atraverse member, a cam for continuously producing reciprocating motionof unvarying characteristics, means for driving said cam and said bobbinin synchronism to produce a pattern wind, means for intermittentlycircumferentially displacing successively wound portions of the pattern,a connecting means for transmitting substantially unimpaired the motionof said cam to the traverse member to effect a constant stroke amplitudethroughout the winding period, and a package contacting thread guidecarried by said traverse member and movable axially of the bobbin todirect the transverse movement of the thread thereon.

10. An apparatus for the bobbin-spinning of rayon comprising a bobbin, atraverse member,

a cam for continuously producing reciprocating motion of a linear speeddirectly proportional to the angular velocity of the'cam, means fordriving said cam and said bobbin in synchronism to produce a patternwind, a connecting means for transmitting substantially unimpaired themotion of said cam to the traverse memberto effect a constant strokeamplitude throughout the winding period, and a package contacting threadguide carried by said traverse member and movable axially of the bobbinto direct the transverse movement of the thread thereon.

11. An apparatus for the bobbin spinning of rayon comprisinga bobbin, atraverse member, a cam for continuouslyproducing reciprocating motion ofa linear speed directly proportional to the angular velocity of the cam,means for driving said cam and said bobbin in synchronism to produce apattern wind, means for intermittently, 'circumferentially displacingsuccessively wound portions of the pattern, a connecting means fortransmitting substantially unimpaired the motion of said cam to thetraverse member to effect a constant stroke amplitude throughout thewinding period, and a package contacting thread guide carried by saidtraverse member and movable axially of the bobbin to direct thetransverse movement of the thread thereon..

12. An apparatus for the bobbin spinning of ireshly spun rayon threadcomprising a thread source, a foraminated thread package collectingbobbin and atraverse bar, a cam for continuously producing reciprocatingmotion of a linear speed directly proportional to the angular velocityof the cam, said cam having a peripheral groove therein, a follower insaid groove, means for confining the movement of said follower to asingle plane, a rod pivotally connected to said follower, the free endof said rod being pivotally attached to an arm, a rock shaft, said armbeing attached to said rock shaft at a point substantially remote fromthe location of the pivot point,

' said rock shaft being driven through said arm by the rod connected tothe cam follower, a traverse bar driven from the rock shaft to which,said arm is attached, a package contacting thread guide carried by saidtraverse bar, and means for driving said cam and bobbin in synchronism.

13. An apparatus for the bobbin spinning of freshly spun rayon threadcomprising a thread source, a foraminated thread package collectinbobbin and a traversebar, a cam for continuously producing reciprocatingmotion of a linear speed directly proportional to the angular velocityof the cam, said cam having a peripheral groove therein, a follower insaid groove, means for confining themovement of said follower to asingle plane, a rod pivotally connected to said follower, the free endof said rod being pivotally attached to an arm, a rock shaft, said armbeing attached to said rock shaft at a point substantially remote fromthe-location of the pivot point, said rock shaft being driven throughsaid arm by the rod connected to the cam follower, a traverse bar drivenfrom the rock shaft to which said arm is attached, a package contactingthread guide carried by said traverse bar, means for driving said camand bobbin in synchronism, and means package beingv characterized by aplurality of superimposed oppositely directed helical courses of threadof equal length cross-wound according to a predetermined flxed pattern,said package being of uniform radial thickness throughout its length andbeing further characterized by having self-supporting square ends andradial channels throughout the body thereof whereby the package may beafter-treated by forcing treating liquid therethrough without physicalinjury to said filaments and with substantially uniform treatment of thefilaments throughout all portions of the package.

ARTHUR JACKSON. I

